My role model for his brains, calm demeanour and appetite for snacks!
I'm assuming if DAS survives interception, they add their factors to the defensive factors (after DM has been applied) as if they hadnt been intercepted? And post interception, if the odds are in the defenders favor, could they choose to return to base rather then risk getting a bad roll and being eliminated in the ensuing combat?
DAS can only add their factors to the defence strength of the hex if they survive and are not compelled to abort by the interception air combat result.
If they meet both criteria, they can choose to cancel their DAS mission and return to base without risk of further losses.
Rule Book wrote:
18.563 RESOLVING INTERCEPTION OF DEFENSIVE AIR SUPPORT:
18.5631 When defensive air support is intercepted, at least one round of air combat between the intercepting and defending air units is resolved. The defender then has the option of returning to base or continuing his defensive air support mission.
18.5632 If the defending air units which survived the initial round of air combat elect to return to base, their defensive air support mission is canceled and no additional rounds of air combat take place.
18.5633 If the defending air units which survived the initial round of air combat elect to continue their defensive air support mission, all defending air factors which were neither eliminated nor forced to abort by the attacker’s final air combat dice roll (the number after the “/” on the Air Combat Table) provide defensive air support (subject to 18.614), unless the attacker elects to fight another round of air combat.
18.5634 If the defender elects to continue his defensive air support, the attacker may initiate a second round of air combat with his surviving air units, including those forced to abort by the defender's previous air combat dice roll; may reinforce his interception with additional, previously uncommitted air units, whether or not any intercepting air units survived the previous round of air combat; or disengage. All air units flying defensive air support which were not eliminated in previous rounds of air combat must be engaged, including those which were forced to abort in the previous air combat round. This continues until one side or the other disengages or is completely eliminated.